白芦笋选择采收机器人关键部件设计与试验

Design and Experiment of Key Components for Selective White Asparagus Harvesting Robot

摘要:

针对白芦笋采收劳动强度大、作业效率低等问题,设计了一种白芦笋采收机器人。根据白芦笋的种植和采收特点,对白芦笋整机结构和控制系统进行了研究;分析了白芦笋采收的主要动作流程,确定白芦笋采收末端执行器的主要结构和核心设计参数,建立了白芦笋采收MBD-DEM复合的离散元运动联合仿真模型,校验设计参数合理性。仿真试验表明,末端执行器下插动作所需推力为580.2N,土中横刀动作所需推力为44.2N;以下刀位置倍数、切割距离倍数和末端执行器距垄面高度为指标进行三因素三水平的正交试验,最优采收参数组合为:下刀位置倍数1.2、切割距离倍数1.2、末端执行器距垄面高度5cm;大田采收试验表明,实际笋芽识别成功率为90.2%,平均检测时间为23ms,成功识别笋芽的平均采收成功率为92.7%,平均单次定位时间1.7s,平均单次采收动作时间3.2s;芦笋损伤率为4.3%。

Abstract:

A white asparagus harvesting robot was designed to address the high labor intensity and low operational efficiency associated with manual harvesting. Based on the planting and harvesting characteristics of white asparagus, the overall structure and control system of the robot were investigated. The primary motion sequence of the harvesting process was analyzed to determine the main structure and core design parameters of the end-effector. The robot was configured for continuous ridge-straddling operation, in which visual detection, lateral positioning, blade insertion, in-soil cutting, lifting, and discharge were coordinated without stopping. An MBD-DEM (Multi-body dynamics and discrete element method) coupled simulation model was established to verify the rationality of the design parameters. Simulation results indicated that the thrust required for the end-effector??s insertion was 580. 2 N, and the thrust required for the horizontal cutting action in the soil was 44. 2 N. A three-factor, three-level orthogonal experiment was conducted using the cutting position multiplier, cutting distance multiplier, and the height of the end-effector relative to the ridge surface as indices. The results showed that the optimal harvesting parameter combination was a cutting position multiplier of 1. 2, a cutting distance multiplier of 1. 2, and a height of 5 cm. Field experiments demonstrated an actual spear recognition success rate of 90. 2% with an average detection time of 23 ms. For successfully recognized spears, the harvesting success rate was 92. 7% , with an average single positioning time of 1. 7 s and an average single harvesting cycle time of 3. 2 s. The asparagus damage rate was found to be 4. 3% . These results provide a basis for optimizing selective harvesting equipment for white asparagus grown on high ridges under field conditions.